Vaghi



Aug. 11, 1959 J. VAGHI AIR CIRCULATINGBLOWER 3 Sheets-Sheek. 1

Filed Feb. 12', 1957 mull a m my m V Aug. 11, 1959 J. VAGHI 2,899,128

AIR CIRCULATING BLOWER Filed Feb. 12, 1957 3 Sheets-Sheet 2 INVENTOR ATTORNEYS,

J. VAGHI AIR CIRCULATING BLOWER I5 Sheets-Sheet 3 Filed Feb. 12, 1957 /INVENTOR BY Z ATTORNEYS United States Patent AIR CIRCULATING BLOWER Joseph Vaghi, Bethe], Conn.

Application February 12, 1957, Serial No. 639,681

Claims. (Cl. 230-117) This invention relates to an air circulating blower, and has for an object to provide an improved form of fan in combination with a housing or enclosing guard to secure a strong, concentrated stream of air for quickly renewing or changing the air in a room, rather than to secure a dispersed or slowly moving or circulating air, as for cooling purposes with the ordinary fan, and thus may be employed, for example, to blow out the hot air in the upper part of a room and let fresh, cool air from the outside come in to replace it within a short time.

It is also an object to provide an improved form of fan blade in combination with an improved form of enclosing housing or guard to secure greater efiiciency and movement of air with less power.

With the foregoing and other objects in view, I have devised the construction illustrated in the accompanying drawings forming a part of this specification. It is, however, to be understood the invention is not limited to the specific details of construction and arrangement shown, but may embody various changes and modifications within the scope of the invention.

In these drawings:

Fig. 1 is a front view of the device;

Fig. 2 is a top plan viewon a reduced scale;

.Fig. 3 is a partial side elevation and partial section;

Fig. 4 is a detail section of one edge portion of the housing and guard showing the relation of a fan blade thereto;.

Fig..5 is a rear side view of the free end portion of the blade;

Fig. 6 isa view of the blade looking from. the front of the fan;

Fig. 7 is a view of the blade looking toward the side of .the fan;

Fig. 8 is an edge View looking toward the wavy or corrugated trailing edge;

.Figs. 9, and 11 are transverse sections of the blade taken substantially on lines 99, 1010 and 111I respectively of Fig. 6;

Fig. 12 is a side viewshowing the blower on a diiferent form of supporting stand, with parts brokenaway;

Fig. 13 is a rear view thereof looking from the right of Fig. 12;

Fig. 14 is a bottom view ofthe base portion of this stand;

Fig. .15 is a plan view of a control which may be used;

'.Fig. 16is a transverse section on an enlarged scale substantially on line 16-16 ofFig. 12 of a clamping means for the upright portion of the stand;

Fig. 17 is a side view-thereof, and

Fig. 18 is a partial side elevation and partial section showing an effective use of the device for rapidly changing the airin 3:1'0011'1r' The improved blower comprises a circular ring guard or housing 1 open at the front and rear and supported by a suitable bracket 2 on a base 3 through an upstanding support 4 and a pivotal connection 5 between the bracket 2,899,128 Patented Aug. 11, 1959 and the support. The support may include a forked portion 6 between which extends an extension 7 of the guard, and the opposite sides of the guard clamped thereon by a clamping screw 8 to secure the blower in different angular positions.

Mounted within the guard or housing is the fan 9 of a special construction to cooperate with the guard in a novel and improved manner, this fan being mounted on a shaft 10 of the electric motor 11 mounted in the guard by a suitable supporting bracket 12 secured at its lower end to the guard and including a strap or band 13 embracing the motor housing.

The guard or housing 1 comprises an outwardly tapered rearward portion 14 on the inlet side and a cylindrical front portion 15 on the outlet side. Different diameters for these parts may be used depending on the capacity and use desired, but in an effective size for normal house use the tapered portion .14 may be about fourteen inches in its largest diameter and the front cylindrical portion 15 about twelve inches in diameter, with the total width of the guard about three inches and the width of the cylindrical portion 15 about 1% inch.

The fan preferably comprises three blades 16 and is located in the cylindrical portion 15 and blows air forwardly as indicated by the arrow 17. It is driven by an electric motor 11 supplied with current from any suitable source of power, with a suitable connecting conductor cord (not shown) from any suitable outlet connection in the house wiring system.

The tapered rear portion 14 provides an enlarged inlet v to the guard or fan enclosing ring which takes in more air than would flow to the fan otherwise, and due to the taper this air is compressed somewhat and is therefore denser when it reaches the fan blades, getting more efiiciency and greater air flow than would otherwise be the case. Also, this with the cylindrical portion, secures a better effect, as they prevent the air spreading out and fiowing off the ends of the fan blades, and thus produce a stronger and less spread-out stream 18, as shown in Fig. 18, whichcan be directed to the open upper portion 19 of an open window 20, for example, to force out hot air from the room and draw in the cool outside air through the lower open portion of the window, as indicated at 21. The swivel 5 permits swinging the blower to different angular positions about a horizontal axis. A wire grill or protection for the fan and persons using it is provided at 14a at the rear or entrance side of the circular guard, and a similar removable wire screen 15a on the front or exit side. This latter may include lateral loops 15b slipped over lugs on the guard.

There is believed to be a special coaction and new and improved eifect secured by the combination of this form of guard 1 enclosing the fan and the form of fan blades as shown, comprising a straight leading edge 22 and a corrugated or wavy trailing edge 23, these waves or corrugations being relatively large, there being about five of the convex ridges 24 in a blade about five or five and one-half inches long. The curves of the ridges and grooves preferably have substantially the same radii and adjacent curves are tangent to each other. This blade is also wider at its outer end 25' than at its inner end 26 adjacent the hub 27, with a progressive increase from the inner to the outer end, it being preferably about one and one-half inches wide at its outer end and about seveneighths inch wide at its inner end. By this wavy trailing edge with alternate ridges 24 and grooves 28 with these ribs and grooves tapering from a maximum at the wavy edge 23 to nothing adjacent the midwidth or about half way across the blade, as indicated at 29, is thus provided varied pitches throughout the blade with a maximum pitch at the edges 23 at the tops of the ribs, and a minimum at the bottom of the grooves or channels. This may thus be called a two-pitch blade, although the pitch varies between the maximum and minimum. The blade in cross section has preferably an airfoil section with a transverse convexly curved back surface 9a, and a relatively sharp leading edge 22. With a sharp leading edge there is no bump in the :air stream to deflect the air laterally. The shape is substantially that shown in Figs. 9 to 11, with the pitch varying and progressively decreasing from the inner end next to the hub 27 to the outer end 25, with less inclination to the axis of the hub and therefore the axis of rotation -at the end nearest the hub, as shown in Fig. 9, and the greater inclination being at the outer end, as shown in Fig. 11, with a gradual variation between these two, an intermediate inclination being shown in Fig. 10. The straight leading edge 22 is preferably substantially tangent to the outer surface of the hub, as shown in Fig. 6, with wavy trailing edge 22 running into the hub at about its center in alignment with its center axis. A line A through the axis and parallel to the leading edge 22 substantially bisects the outer wider end 25.

This wavy contour of the blades prevents air from flowing off the ends of the blades and causes it to pile up in a channel between the ridges. Its outer end terminates with a concave channel 28a (Fig. '8) on the front or air-impelling side of the blade. This shape also increases the surface of the blade, giving it a greater grip or resistance on the air for a given length and width of blade, and materially increases the length of the trailing edge. There seems to be a definite coaction and improved action between the fan comprising this form of blade and the combined taper and cylindrical guard closely surrounding the free ends of the blades, which produces a very strong, concentrated stream of air, which does not spread out as in the ordinary circulating fan. The corrugations of the blade, as well as the closely located cylindrical portion 15 of the guard, and the two-pitch effect (wavy or corrugated shape) secure a better effect and reduce the spread-out of air 01f the ends of the blades over that of the plain type of blade. With the forward edge 1512 (Fig. 4) of the guard only a short distance in front of the forward edge 23 of the blade, much better results are secured as there is no drag, more air is discharged with less resistance, and there is no material spreading of the air stream.

In Figs. 12 to 18 is shown a modified form of stand which may be used to hold the blower at a greater height above a floor, for example, and also facilitates moving the blower between different locations, and is effective in placing it in front of a half-opened window, as shown in Fig. 18, for most eifective operation, changing the air in a room, for example. This stand support comprises a base 30 of general triangular shape having supporting rollers 31 at its widest end on which it may be shifted, and corrugated or roughened rubber pad 32 on its under side at its narrower end to grip the surface of the floor and prevent it from shifting under action of the fan. Mounted on the base is an upright tubular support 33 comprising a lower section 34 and an upper section 35 telescoped therewith to the upper end of which the guard of the blower may be swivelly connected, as indicated at 36. This tubular support provides convenient means for leading conductor wires 37 from the base to the fan motor, the speed of which may be controlled by a suitable lever controlled rheostat 38 with a plug-in cord 39 passing through a suitable tubular handle 40 to this control, this handle having a suitable hand grip 41, and mounted at its lower end in a fork 42 pivoted to the base at 43 with a suitable on-and-off hand switch 44. The height of the blower may be adjusted by adjusting the 4 position of the upper section 35 of the stand in the lower section 34. A simple and effective means for retaining it in different adjusted positions .is to provide the lower section 34 with a tapered, screw-threaded slit upper end 45 and a clamping handle 46 threaded onto this tapered portion and with turning action adapted to clamp it onto the section 35.

This new combination and construction provides a blower which will give a strong concentrated stream of air for quickly renewing or changing the air in a room, rather than providing a dispersed, slowly moving circulating air as commonly secured with the usual cooling fan, and will produce this strong stream more effectively and with greater efiiciency. It compresses the entering air from its natural state, first by the enlarged tapered inlet on the guard ring around the propeller or fan, and second by the blades themselves by means of the corrugations by forcing the air through the corrugations. Resistance to air taken in or obstruction to it is reduced to a minimum. The improved stand of Figs. 12 to 18 permits ready shifting of the blower to any desired position for more quickly changing the air in a room, as, for example,

7 as illustrated in Fig. 18, and also provides for effective control of operation of the blower.

Having thus set forth the nature of my invention, I claim:

1. An air circulating blower comprising a rotary fan including a central hub and a plurality of radial blades extending outwardly from the hub, each blade being laterally inclined to the axis of the hub and comprising a straight relatively sharp leading edge and a wavy alternately convexly and concavely curved trailing edge with alternate transverse convex ridges and concave grooves extending inwardly from the wavy edge and gradually decreasing in height and depth respectively to substantially half way across the blade, the width of the blade increasing progressively from its inner to its outer end, and the outer end terminating with a concave channel on the front and air-impelling side of the blade.

2. An air circulating blower according to claim 1 in which the inclination of the blade to the axis of rotation increases progressively from its inner to its outer end.

3. An air circulating blower according to claim 1 in which the adjacent curves are substantially tangent to each other.

4. An air circulating blower according to claim 1 in which the straight edge of the blade is substantially tangent to the surface of the hub and the wavy edge is in substantial alignment with the axis of the hub.

5. An air circulating blower according to claim 1 in which the fan is mounted in an outer circular housing and guard including an outwardly tapered inlet portion and a substantially cylindrical outlet portion forming a continuation of the inner reduced end of the tapered portion, the fan is mounted in the cylindrical portion with the outer ends of the blades adjacent the inner surface of this portion and the cylindrical portion terminates in substantially the plane of the rear edges of the blades, and a power means for operating the fan.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS 49 Great Britain of 1915 

